Quality control of urban soil samples from Tampere, Heinola and Lahti

This document sets out guidelines for the implementation of Quality Control (QC) program on an urban soil geochemical dataset, covering data from the geographical area of three cities of Finland, Tampere, Lahti and Heinola, to assess and interpret data quality. In order to provide accurate and reliable data, the Geological Survey of Finland (GTK) has established a QC program in which the control samples data are systematically evaluated. In practice, fitness for purpose is determined by a comparison of the accuracy achieved in laboratory with a required level of accuracy. QC program is undertaken by the inclusion of particular reference materials, project standard materials as well as field and analytical duplicates into the analytical sequence. Tabulated and graphical summaries of the data are presented. In most cases, the QC program demonstrates reasonably acceptable analysis results of geochemical data from Tampere, Lahti and Heinola soil samples.